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Old 10-04-2021, 07:09 PM
BobTurner BobTurner is online now
Join Date: Dec 2011
Location: Livermore, CA
Posts: 8,242

You seem to be trying to use the fuel flow apertures to adjust the CHT. Not the right approach.
1. Do the so-called Gami test: slowly lean, and note the fuel flow when each cylinder reaches peak EGT. Do this for your favorite cruise condition.
2. Note the first to peak (going rich to lean) is the leanest cylinder. Increase the diameter of the injector aperture for that cylinder. Last to peak is the richest. Decrease its aperture size. etc. etc., until they all reach peak EGT at nearly the same time, as you slowly lean.
3. Check that you are still getting minimum fuel flow (24 gal/hr IIRC) at full throttle seal level takeoff.
Now attack any CHT issues, by adjusting cooling air/baffling. Many insert a washer between the aft cylinder and the baffling to get more air in there, although that's usually for #5. Use RTV to seal up all escape paths for the cooling air. Double check that all baffling is in proper place.
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